OK, I finally have found time to analyze this and discuss with gg (for more correct interpretation).

When cursor / selection start time in your sample .mp4 file is about at:

0:00:46:00  -- stitching in this DAW-like feature requires an exact algorithm and the timeline alignment is what creates the binding and allows for ganging.  Tracks are not inherently bound or in a container.  It was hoped that instead of the implemented method, he could use a container and end up with something like both stereo channels, for example, always in the same track container (like the DAW software).  He started coding using mixer containers but management of that became untenable.  Anyway for ganging to work as expected, the tracks have to be lined up at the beginning.

0:00:59:00 -- concerning not being able to drop to align the video and audio, if you look very carefully at around this time in the video when the drag bars show up, the yellow colored compass icon very center point is actually on the video track.  And since you can not drag an audio track to a video track that is why it does not drop.  You have to make sure that the exact center point of this oversized compass icon is on an audio track.  The way we align these back up again is to use the "down arrow" on the keyboard to zoom in on the images and drag more carefully (of course you will have to enable "align on frames". There are probably better ways to do this too.

0:01:14:00 -- you can move them together again in the gang_none mode by Left Mouse Button click on each of the tracks to be moved together, which puts a highlight box around them so you can see that they move together.  Left mouse click to turn off the highlight group move.  You can also make permanent groups that always move together but that is for another day.

0:01:57:00 -- yes, disarmed tracks are definitely ignored when in ganging mode.  The main reason being the whole point of ganging is to keep your tracks looking the same with cuts, edits, and plugins.  I did document this.  In addition I have to add to the document that the permanent groups as mentioned in the previous timestamp do not take precedence over ganging; i.e. they are ignored and only the timeline alignment is honored.

More later.

When I finally tested this, I found that while I thought I was dragging the waveform audio to the beginning of the track, there was actually silent space in front of the audio waveform so it really is dragging to the beginning but you have to cut that blank part off.  Not at all what is expected either.

I don't quite understand what you mean here. But imagine that "x" was applied, that would mean that everything in the armed track(s) would get moved. How could everything (not a single item) be moved back (even manually) if that mistake was spotted far beyond a realistic "undo" ability?

"A configuration option for a key binding would not revolt users" -- YES, this is a much better solution and has been requested by many, many users and over many years -- it is about the only really important feature left to implement.   It is a difficult mod to make and would take a lot of time but hopefully it will happen some day.  Then instead of a revolt, there would be a BIG party.

About "Specifically why isn't dragging to the start of another track not 'enough'?"  When I finally tested this, I found that while I thought I was dragging the waveform audio to the beginning of the track, there was actually silent space in front of the audio waveform so it really is dragging to the beginning but you have to cut that blank part off.  Not at all what is expected either.

instead of using "x" for cut, why not just use "m" for mute? <- because I am using "delete", so I would love to be able to map delete to "mute" ;-) A configuration option for a key binding would not revolt users ;-)

"How to align track back to the right place?" -- I think if you temporarily change Settings->Align cursor on frames    you can get them to line back up.

"Specifically why isn't dragging to the start of another track not 'enough'?"  -  I still have to test this to see why that does not work -- it probably should.

"why "mute" isn't the default cut action, and why it can't be configured to just have cut always to mute, instead of moving tracks."  -- instead of using "x" for cut, why not just use "m" for mute?  Changing the default actions would lead to a revolt !  All of the grouping in Drag and Drop mode was an addition about 2-3 years ago and that was the decision at the time.

P.S. I am not an expert on using Cinelerra so I can not keep up!!

What is your suggestion for 'recovery' of mistakes? How to align track back to the right place? Specifically why isn't dragging to the start of another track not 'enough'? This does not seem to be a crazy thing to have just working?

I am also interested why "mute" isn't the default cut action, and why it can't be configured to just have cut always to mute, instead of moving tracks.

About     https://streamable.com/wmvk9d

Right now adding a new Video track always goes on the top and adding a new Audio track goes on the bottom.  GG would really like to change this to add any new tracks on the bottom as it makes more sense. However, whenever changing operations that have existed since the beginning, we have to be pretty sure that pre-existing projects will not be impacted and this is not easy to do.

The best method to add new Video/Audio tracks in this case is to use the pulldown

     Tracks->Append to Project -- shortcut Shift-N

especially now with the new "DAW-like" mode because this ensures that the "Master Track" will be enabled on the first newly added track.  If instead you use the current methodology shown in your video, the newly added video and audio tracks are considered to be part of the same "gang" as your current tracks.  If you want it to be treated as part of the same gang, you will have to toggle off the "Master Track" button.

As shown in your video, the arming/disarming of tracks is a nuisance and leads to making mistakes -- one of the major goals of implementing gang_channels was to avoid mistakes with forgetting to arm/disarm tracks.

Comments?? ideas??

Good!  I downloaded them.  They will help to see if we can do something to alleviate the problems.

https://streamable.com/igwuoe

https://streamable.com/wmvk9d